The definition of a HVAC building is a structure that is equipped with a heating, ventilation, and air conditioning system. This type of system is designed to provide a comfortable and safe environment for occupants, while also conserving energy. The heating system is designed to maintain a comfortable temperature in the building, while the ventilation system is designed to provide fresh air and remove pollutants. The air conditioning system is designed to maintain a comfortable humidity level and to reduce the amount of dust and other airborne particles. All of these systems work together to create a healthy and comfortable environment for occupants. HVAC buildings are commonly found in commercial and industrial buildings, as well as in residential homes. They are essential for maintaining a healthy and comfortable environment, while also reducing energy costs.